1. Field of the Invention
This invention relates to electrophotography, and more particularly to an improved apparatus for removing residual toner particles from a surface of a photoconductor.
2. Description of the Prior Art
In known electrophotographic reproduction apparatus such as copiers or non-impact printers, an electrostatic charge is deposited on an area of a photoconductor as the area is moved past a charging station. The photoconductor is then moved to an exposure station where the area is exposed to image-forming radiation to form a latent electrostatic image of information to be reproduced. The latent image is thereafter developed by depositing opaque electroscopic particles, such as toner particles, on the photoconductor and, in the case of plain-paper copiers and non-impact printers, the developed image is subsequently, during a transfer step transferred to paper upon which the copied image is to appear. Thereafter, the photoconductor is cleaned and otherwise made ready for the next copy cycle.
In such apparatus, it is important for ensuring image quality to remove, before the next copy cycle, any residual toner particles remaining on the photoconductor after the transfer step.
In U.S. Pat. No. Re. 28,566, a magnetic brush cleaning roller is described which can be used to remove such residual toner particles. The magnetic brush roller includes bristles or a nap formed of discrete magnetic carrier beads which are carried on a rotating surface of the roller and which upon scrubbing engagement with the surface of the photoconductor are able to remove the toner particles from the photoconductor and retain them in the nap from which the toner particles subsequently can be removed. The toner particles are removed from the nap by placing a detoning roller which comprises an electrically biased metallic surface, in proximity to the nap so that the toner particles are electrostatically removed from the magnetic brush roller onto the detoning roller. The particles are thereafter scraped from the detoning roller and allowed to fall to a catch tray located below the detoning roller. The toner may be allowed to accumulate in the catch tray or as shown in U.S. Pat. No. 4,402,103 the catch tray may be provided with an auger or other conveying means for conveying the toner particles to a developer station or toner recycling station for reuse. While the apparatus described works well in cleaning the photoconductor, scattering of toner particles to other areas than its intended point of collection is made likely by allowing the free fall of toner particles in an environment where air currents are created by rapidly rotating members.
As indicated above, an advantageous feature of a cleaning apparatus is for it to have the ability to convey toner particles from the cleaning station to a collection device for disposal or for recirculation. The use of the toner conveying arrangement indicated above would require an additional means be provided for driving an auger or the like. The addition of the auger and a drive therefor increases the number of moving parts and the size of the charging station.
It is therefore an object of the invention to provide an apparatus which overcomes the disadvantages of the prior art as set forth above.